Stencil cutting die



.lune 17, 1941. 5C, FRANZMANN 22455770 STENCIL CUTTING DIE Filed March 50, 1940 [rauen/23074' (Z Wcz/nzWLGJ/wv may Patented June 17, 1941 FIC STENCIL CUTTING DIE Emile C. Franzmann, Arlington, Mass.

Application March 30, 1940, Serial No. 326,869

7 Claims.

rhis invention relates to a method of and apparatus for sand blasting intaglio designs, as, for example, letters in stone and the like.

Much time and money has been spent in attempts to provide a practical method and means for sand blasting intaglio designs or inscriptions in stone. Various attempts have been made to press heated die members into a gelatinous material which is applied to the surface of a stone by various methods and thereafterutilized as a pattern for the design and also as a protective covering for the remainder of the stone which is located adjacent to that portion thereof which is subjected to the sand blast. Various types of die members have been used, some formed of friabie material and others of metal, as, for example, lead, but all of these die members have been provided with at Working faces and it has been necessary to melt said members into the gelatinous material when forming the design. f

Under such conditions a thin `iilm of vgelatin often remains between the bottom of the die member and the face of the stone, and said lm resists the sand blast operation and is only removed with difficulty. Attempts have been made to avoid the presence of this film by sinking die members through a gelatinous material before the latter is applied to the stone, holding said gelatinous material and die members `together between sheets of paper and the like until they are applied to said stone. When thisfmethod is employed it is necessary to sponge or soak the under layer of paper from the gelatin sheet and to soften the under surface of the latter with hot Water in order to render it sufficiently adhesive to cause it to stick to the stone. This softening of the under surface of the gelatin and the act of positioning the sheet upon the stone usually causes the letters to become distorted. Furthermore, the inner portions of letters like A, B, D, O, etc., are not attached by any other portions of the letter to the portion of the gelatinous material which forms the outer portion of the letter, and said inner portions of said letters are seldom attached with suiiicient security to the/stone to remain permanently thereon during the sand blast operation thereby preventing perfect letters from being formed. It is virtually impossible to securely attach a pre-cut stencil formed of gelatinous material to a stone Without distorting some portion of nearly every letter of the alphabet.

The object of this invention is to provide an improved apparatus and process for sand blasting intaglio designs in stone andthe like, Whereby a design may be cut directly in a sand blast resisting material secured in position upon a stone, making it possible for a cut out inner or core portion of sai-d material to be peeled intact from the stone together With the adhesive therebeneath clinging thereto Without injuring or distorting the cut edges of the design or making it necessary to separately remove any of the adhesive from the face of the stone.

Another object of the invention is to provide an improved type of die member having double line cutting edges and capable of being heated' to a considerable degree Without injury and also of being manually placed in position upon the sand blast resisting material and pressed therethrough .by the hands of a Workman without danger of the latter injuring his hands.

Still another object of the invention is to provide an improved holder for a die member which Will not be injured by heat and which will dissipate heat transmitted thereto from the die member.

The invention consists of an apparatus and method for sand blasting designs and inscriptions i' in stone and the like as setA forth in the following specification and particularly as pointed out in the claims.

Referring to the drawing:

Fig. 1 is a tace View of a die member constituting a portion of the apparatus of this invention. Fig. 2 is a side elevation of said die member.

Fig. 3 is a transverse section'through a die member and holder therefor as taken on the line 3 3 of Fig. 1.

Fig. 4 is a plan view of a piece of stone having a strip of sand blast resisting material applied thereto and the latter having the outline of a letter marked thereon.

Fig. 5 is a view similar to Fig; 4 illustrating the letter of Fig. l cut in the sand blast resisting material by the die member of Fig. 1, a portion of the cut out core portion of the letter being illustrated as peeled or lifted from the stone with the adhesive clinging to the under surface thereof.

Fig. 6 is a View similar to Figs. 4 and 5 illustrating the cut out core portion of the sand blast resisting material entirely removed from the stone.

7, 8 and 9 are enlarged detail sectional views illustrating steps in the operation of forming a design in the sand blast resisting material.

Fig. l0 is a View of the under facev of a piece of sand blast resisting material illustrating the protective material for the adhesive partly stripped therefrom.

Fig. 11 is a sectional view of a modied type of holder for a die member.

Like numerals refer to like parts throughout the several views of the drawing.

In the drawing, I represents a die member formedas a double line letter of the alphabet and constructed of a suitable alloy to produce and retain a sharp cutting edge It capable of being forced by hand pressure through a sheet of sand blast resisting material Il, also called masking tape, Secured to the face of a stone memorial I8. The die member I5 is secured by eyelets IS to a metal holder preferably formed of square or rectangular tubular stock and providing a maximum amount of surface with which air may contact to the end that heat transmitted 'thereto from the die member may be dissipated eectively as it passes upwardly through the side walls of the tube. Openings 2| provided in the side walls of the holder 20 also act to still further dissipate the heat and the side walls of the holder constitute heat dissipating webs therefor. Secured to the opposite face of the holder 2G from that to which the die member I5 is secured is a layer of heat resisting material 22, as, for example, sheet asbestos. superposed on the asbestos 22 is a gripping member 23 also formed of heat resisting material, as, for example, a sheet of closeiy matted felt or similar material which protrudes beyond the sides and ends of the holder 2t in a manner to permit the material to be gripped by a workman and lifted and otherwise manipulated without danger of burning the iingers. of material 22 and 23 are secured to the holder 2G by eyelets 24, the outer extremities of which are sunk deeply into the felt. The die members I5 are heated to a temperature of approximately 450 degrees by direct contact with a heated surc face upon which said members may rest prior to being placed in use.

The sand blast resisting material Il comprises a sheet of rubber composition commercially known as "masking tape, and said material is coated upon one face thereof with a rubber cement 25 which is protected prior to the time that the material II is attached to a stone I8 by a sheet of protective material 25 which is then peeled from the cement 25 as illustrated in Fig. 10. Before the masking tape is applied to the stone I8 a layer of rubber cement is applied to that portion of the surface of said stone that is to have the masking material attached thereto, and

when said material I'I is so applied to said stone the layers of rubber cement will merge to form a single layer.

It is evident that the letters of an inscription must be carefully spaced and that said spacing must ncessarily depend upon the size and character of the letters used. Preferably the inscription is arranged carefully by a designer upon a sheet of paper and isI transferred to the surface of the sand blast resisting material Il in any suitable manner either before or after said material is applied to the stone. Fig. 4 illustrates the outline 2l of a letter F transferred to the surface of the masking material Il, and said outline correspondsI to the cutting edge Iii of the die member I5 illustrated in Fig. l. Fig 'l illustrates a die member i5 penetrating the masking material I'I' and cement 25 and cutting the outline of a letter in said materials. When the die member I5 is removed the material Il appears as illustrated in Figs. 5 and 8, a narrow groove 28 The layers I i having been cut insaid material and a core portion of a letter having been severed from the material. 'Ihe severed core portion 29 is then peeled from the surface of the stone I3 as illustrated in Fig. 5 with all of the adhesive 25 therebeneath clinging thereto. The face of the material I1 then appears as illustrated in Fig. 6 ready to be subjected to the sand blast operation. In section the material I1 appears as illustrated in Fig. 9, the sides of the opening of the letter being slightly bevelled.

After all of the letters of the inscription have been cut in the masking material I'I a sand blast well known in the art is applied thereto in a well known manner and the inscription is cut into the stone to the desired depth, the masking or sand blast resisting material I1 protecting that portion of said stone which is covered thereby. At the end of the sand blast operation the masking material I'I with the adhesive 25 clinging thereto is stripped from the stone.

In Fig. 11 I have illustrated a holder 30 for a die member I5 constructed as an I beam of suitable metal, the die member being secured to the lower flanged portion of said holder, and a layer of asbestos 22 and felt gripping member 23 being attached tothe upper flanged portion of said holder in any suitable manner to permit the holder to be handled as hereinbefore described in connection with the holder 29. The relatively thin vintermediate portion of the I beam constitutes a heat dissipating web.

It will be understood that in positioning the die member upon the masking material Il that a straight edge, triangle, and other suitable instruments may be utilized to facilitate the accurate positioning of said die members and the consequent accurate alignment of the several letters of the inscription.

I claim:

1. In combination, a holder provided with upper and lower body portions connected one to another by a relatively thin heat dissipating web, a die member fast to the under face of said lower body portion, a heat resisting material fast to the upper face of said upper body portion, and a gripping member of heat resisting material superposed upon said rst named heat resisting material.

2. In combination, a holder provided with upper and lower body portions connected one to another by a relatively thin heat dissipating web, a double line cutting die fast to the under face of said lower body portion, a heat resisting material fast to the upper face of said upper body portion, and a gripping member also of heat resisting material superposed upon said first named heat resisting material and projecting beyond the edges of the latter.

3. In combination, a holder provided with upper and lower body portions connected one to another by a thin heat dissipating web and having an air circulating space therebetween, a cutting die fast to the under face of said lower body portion, and a graspable member of heat resisting material fast to the upper face of the upper body portion.

4. In combination, a holder provided with upper and lower body portions connected one to another by a thin heat dissipating web opposite faces of which are exposed to air, a cutting die fast to the under face of said lower body portion and an upper surface of the latter being exposed to air, and a graspable member of heat resisting material fast to the upper face of said upper body face of said upper body portion and an under l0 surface of the latter being exposed to air, and a graspable member of felt superposed upon said asbestos.

6. In combination, a non-combustible holder Cil of rectangular tubular formation having thin heat dissipating walls and an air circulating space therebetween, a cutting die fast to the under face of the lowermost wall, and a graspable member of heat resistable material fast to the upper face of the uppermost wall.

7. In combination, a non-'combustible holder of I-beam formation having thin upper and lower anges and thin connecting web all of which are exposed to air, a cutting die fast to the under face of the lowermost flanges, and a graspable member of heat resisting material fast to the upper face of the uppermost flanges.

EMILE C. FRANZMANN. 

